Our long term objective is to understand molecular events controlling salivary secretion in ixodid ticks. It is widely believed that disease causing agents are transmitted to the host in secretion from the salivary glands of ticks. We will continue to study the involvement of CA++, cyclic AMP and protein phosphorylation in controlling the fluid secretory process. An adenylate cyclse catalyzes the formation of cyclic AMP from ATP. We will investigate the roles for GTP, CA++, CA++-dependent activator protein CDR or calmodulin) and soluble cytoplasmic factors in the enzyme complex and we will test the ability of various known receptor antagonists to inhibit agonist stimulated activity to establish the nature of the receptor. Enzyme activity will be compared in glands obtained from ticks of different weight because weight is a good indicator of secretory capability of glands. The action of cyclic AMP in a wide variety of cells is expressed through the activation of protein kinases. We will study cyclic AMP dependent protein kinase activity in tick salivary glands. Possible isozymes, inhibitor(s), effects of CA++, enzyme compartmentalization and possible differences in kinase activity in salivary glands of ticks of different weight (state of feeding and maximum secretory capability of galnds) will be investigated. The specificity of cyclic AMP action (and sometimes CA++) is thought to reside in the specific endogenous substrate proteins which are phosphorylated by the cyclic AMP or CA++-dependent protein kinases. For that reason we will continue to investigate and compare cyclic AMP stimulated protein phosphorylation in salivary glands of ticks of different weight. Both intact cells and cell-free systems will be used to study the phosphorylation of endogenous proteins.